JPH10298527A - Epoxy resin-based adhesive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition excellent in adhesiveness especially at high temperature, by using an epoxy resin as a main agent and a specific modified amidoamine as a curing agent. SOLUTION: This composition is obtained by compounding (A) an epoxy resin [e.g. an alkylidene bisphenol polyglycidyl ether of the formula [(R3 and R4 are each H or an alkyl; (m) is 0-2)] as a main agent with (B) a modified amidoamine of the formula, A-NH-CO-CH(R)CH2 -NH-B [A and B are each the residue after removal of one amino group from a polyamine compound (e.g. an aliphatic amine) containing a bifunctional or polyfunctional amino group; R is H or alkyl] as a curing agent. Preferably 100 pts.wt. of the component A is compounded with 5 150 pts.wt. of the component B. The composition is used together with a coupling agent (e.g. vinyltriethoxysilane) to give a composition excellent adhesion retaining properties at high temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin-based adhesive composition, and more particularly, to an epoxy resin having an excellent adhesiveness, particularly an adhesive at high temperatures, using a specific modified amidoamine as a curing agent. The present invention relates to a resin-based adhesive composition.

[0002]

2. Description of the Related Art As a method for joining structural members such as automobiles, ships, and aircraft, there are mechanical joining such as bolts and rivets and fusion such as arc welding and spot welding. However, bonding using an adhesive has advantages such that the bonding surface can be widened, the resistance to repeated fatigue is large, bonding between different materials is possible, and the weight can be reduced.

[0003] However, the method using the structural adhesive has a drawback that durability, particularly durability under the influence of heat, is insufficient.

[0004] Epoxy resins are widely used in a wide range of industries such as automobiles, vehicles, aircraft, electric machines, electronics, architecture, civil engineering, etc., because of their excellent adhesion and durability to adherends such as metals, stones, concrete and plastics. It has been used as a structural adhesive in the field.

Until now, for example, Japanese Patent Application Laid-Open No. 6-2874
No. 10 discloses a specific acrylic polymer resin fine particles,
An epoxy resin-based structural adhesive composition comprising a specific phosphoric acid triester, a bisphenol-type epoxy resin and a heat-active type curing agent has been proposed, and is disclosed in JP-A-6-287411.
Japanese Patent Application Laid-Open Publication No. H11-216, proposes an epoxy resin-based structural adhesive composition comprising a bisphenol-type epoxy resin, a heat-active curing agent, dibenzylidene sorbitol, an acrylic core / shell polymer, and a specific phosphoric acid triester. In particular, no satisfactory performance has been obtained with respect to adhesiveness at high temperatures.

[0006] Japanese Patent Application Laid-Open No. H5-222258 discloses that
Blocking isocyanate as an adhesion promoter and α, β
-A vinyl chloride plastisol composition comprising a modified amidoamine obtained from an unsaturated carboxylic acid or an ester thereof and a polyamine compound has been proposed, but the modified amidoamine used here can be used as a curing agent for an epoxy resin. Is not described at all.

Accordingly, it is an object of the present invention to provide an epoxy resin-based adhesive composition having significantly improved adhesiveness, particularly at high temperatures.

[0008]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that the above object can be achieved by using an epoxy resin as a main component and a specific modified amidoamine as a curing agent. .

The present invention has been made based on the above findings, and is based on an epoxy resin comprising an epoxy resin and a modified amidoamine represented by the following general formula (I) of the following [Chemical Formula 3] (same as the above [Chemical Formula 1]). An adhesive composition is provided.

[0010]

Embedded image

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the epoxy resin-based adhesive composition of the present invention will be described in detail.

The epoxy resin used in the present invention is used as a main ingredient of the composition of the present invention. Examples thereof include polyglycidyl, a mononuclear polyhydric phenol compound such as hydroquinone, resorcin, methylresorcin, pyrocatechol, and phloroglucinol. Ether compounds: dihydroxynaphthalene, biphenol, methylenebisphenol (bisphenol F), methylenebis (orthocresol),
Ethylidene bisphenol, isopropylidene bisphenol (bisphenol A), isopropylidene bis (orthocresol), tetrabromobisphenol A, 1,3-bis (4-hydroxycumylbenzene),
1,4-bis (4-hydroxycumylbenzene), 1,
1,3-tris (4-hydroxyphenyl) butane,
Polyglycidyl ether compounds of polynuclear polyhydric phenol compounds such as 1,1,2,2-tetra (4-hydroxyphenyl) ethane, thiobisphenol, sulfobisphenol, oxybisphenol, phenol novolak, orthocresol novolak, resorcinol novolak; ethylene glycol , Propylene glycol, butylene glycol, hexanediol, polyglycol,
Polyglycidyl ethers of polyhydric alcohols such as thiodiglycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, bisphenol A-ethylene oxide adduct; maleic acid, fumaric acid,
Itaconic acid, succinic acid, glutaric acid, suberic acid, adipic acid, azelaic acid, sebacic acid, dimer acid, trimer acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, trimesic acid, pyromellitic acid, tetrahydrophthalic acid Glycidyl esters of aliphatic, aromatic or alicyclic polybasic acids such as hexahydrophthalic acid, endomethylenetetrahydrophthalic acid and the like, and homopolymers or copolymers of glycidyl methacrylate; N, N-diglycidylaniline, bis Epoxy compounds having a glycidylamino group such as (4- (N-methyl-N-glycidylamino) phenyl) methane; vinylcyclohexene diepoxide, dicyclopentadiene diepoxide, 3,
4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-
6-methylcyclohexylmethyl-3,4-epoxy-
Epoxidized products of cyclic olefin compounds such as 6-methylcyclohexanecarboxylate and bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate; epoxidized polybutadiene, epoxidized styrene-
Epoxidized conjugated diene polymers such as butadiene copolymers,
And heterocyclic compounds such as triglycidyl isocyanurate.

Among these epoxy resins, in particular, when at least one polyglycidyl ether compound selected from the group consisting of mononuclear polyhydric phenol or polyglycidyl ether of polynuclear polyhydric phenol and aliphatic polyglycidyl ether is used. In particular, the following [Chemical Formula 4]
When the epoxy resin (polyglycidyl ether of alkylidene bisphenol) represented by the general formula (II) (same as the above [Chemical Formula 2]) is used, the epoxy resin composition is excellent in corrosion resistance, adhesion to a substrate, and the like. Is preferred.

[0014]

Embedded image

The alkyl group represented by R ₃ and R ₄ in the general formula (II) includes, for example, methyl, ethyl,
Groups such as propyl and butyl.

Further, phosphoric acid,
Various modified products of dimer acid, NBR, urethane, tannic acid and the like can also be used.

The modified amidoamine represented by the general formula (I) used in the present invention is used as a curing agent for the epoxy resin. In the above general formula (I), R
Examples of the alkyl group represented by are, for example, groups such as methyl, ethyl, and propyl. Examples of the polyamine compound that can constitute the residues represented by A and B include, for example, ethylenediamine, diethylenetriamine, and triamine. Chain aliphatic amines such as ethylenetetramine, tetraethylenepentamine, hexamethylenediamine, polyoxypropylenediamine, polyoxypropylenetriamine; mensendiamine, isophoronediamine, bis (4-amino-3-methylcyclohexyl) methane;
Diaminodicyclohexylmethane, bis (aminomethyl) cyclohexane, N-aminoethylpiperazine,
3,9-bis (3-aminopropyl) -2,4,8,1
Cycloaliphatic amines such as 0-tetraoxaspiro (5.5) undecane; araliphatic amines such as m-xylenediamine; methane such as metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, and diaminodiethylmethylphene; Aromatic polyamines such as α'-bis (4-aminophenyl) -p-diisopropylbenzene and the like can be mentioned. In particular, aliphatic amines (chain aliphatic amine, cycloaliphatic amine or araliphatic amine)
The use of is preferred because excellent adhesiveness can be obtained.

The modified amidoamine represented by the above general formula (I) is preferably, for example, 1.5 to 2.5 moles of the polyamine compound per mole of α, β-unsaturated carboxylic acid or its ester compound. Moles, more preferably 1.
It can be easily obtained by reacting 8 to 2.2 mol.
This reaction is caused by a first-stage reaction in which the polyamine compound reacts with a vinyl group and a second-stage reaction in which the polyamine compound reacts with a carboxyl group or an ester group. Is carried out by dropping an α, β-unsaturated carboxylic acid or its ester compound to the polyamine compound at 30 ° C. or lower, and the second-stage reaction is carried out under normal pressure at 120 to 200 ° C., preferably 1 to 200 ° C.
40 to 180 ° C for 1 to 10 hours, preferably 1.5 to
It is obtained by performing over 5 hours. However, the production method is not particularly limited.

The α, β-unsaturated carboxylic acid or its ester compound includes, for example, acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, isobutyl acrylate, methallyl Acids, t-butyl methacrylate and the like.

The modified amidoamine may be reacted with a dicarboxylic acid such as dimer acid in a conventional manner to give a polyamidoamine, or modified by addition of epoxy resin or modified by addition of acrylonitrile or the like by Michael addition. Is possible.

The modified amidoamine is an epoxy resin 1
The amount is preferably 5 to 150 parts by weight, more preferably 10 to 100 parts by weight, per 100 parts by weight. If the amount of the modified amidoamine is less than 5 parts by weight, the curing rate is extremely poor, which is not preferable. If the amount is more than 150 parts by weight, not only is it meaningless, but also the cured property (adhesiveness) is deteriorated. It is not preferable because it may have an adverse effect.

The epoxy resin-based adhesive composition of the present invention may be used in combination with a usual epoxy resin curing agent. Examples of such a curing agent include diethylene triamine, triethylene tetramine, tetraethylene Chain aliphatic amines such as ethylenepentamine, polyoxypropylenediamine and polyoxypropylenetriamine; mensendiamine, isophoronediamine, bis (4-amino-3-methyldicyclohexyl) methane, diaminodicyclohexylmethane, bis (aminomethyl) Cyclohexane, N-aminoethylpiperazine, 3,9-bis (3
A cycloaliphatic amine such as -aminopropyl) -2,4,8,10-tetraoxoosaspiro (5.5) undecane;
araliphatic amines such as m-xylenediamine; metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, diaminodiethyldimethylphenylmethane, α, α'-bis (4-aminophenyl) -p
A polyamine curing agent such as an aromatic polyamine such as diisopropylbenzene, a polyamide polyamine curing agent obtained by reacting these polyamines with a dicarboxylic acid such as dimer acid, or an epoxy resin added to these polyamines. Epoxy modified polyamine curing agent or Michael addition modified polyamine curing agent to which acrylonitrile or the like is added, and latent curing agents such as dicyandiamide, acid anhydrides and imidazoles can also be used.

The epoxy resin-based adhesive composition of the present invention is preferably used in combination with a coupling agent, since a composition having excellent adhesion retention at high temperatures can be obtained.

Examples of the coupling agent include silane-based, titanate-based, and aluminum-based coupling agents. Among them, a silane-based coupling agent is particularly preferable. Triethoxysilane, vinyltoluchlorosilane, γ-methacryloxypropyltrimethoxysilane,
γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-mercaptopropylethoxysilane, γ- [bis (β-hydroxyethyl)] aminopropyltriethoxysilane and the like. The coupling agent is preferably added in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the epoxy resin.

The epoxy resin-based adhesive composition of the present invention may optionally contain a curing accelerator, a filler, a pigment, an elasticity-imparting agent, and the like.

Examples of the curing accelerator include various curing accelerators such as alcohol, phenol, mercaptan, dimethylurea, aliphatic, and imidazole.

Examples of the filler include glass fiber, cellulose, silica sand, cement, kaolin, clay, aluminum hydroxide, bentonite, talc, silica, finely divided silica, titanium dioxide, calcium carbonate, carbon black, graphite, Examples include iron oxide and bituminous substances.

Examples of the pigment include titanium dioxide, litharge, lithobon, zinc oxide, carbon black and the like.

Examples of the elasticity imparting agent include acrylic rubber, carboxy-modified nitrile rubber, polyurethane resin, silicone resin and the like.

The epoxy resin adhesive composition of the present invention can be dissolved in a solvent to form a solution or an emulsion in order to improve the handleability.

Examples of the solvent include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; esters such as ethyl acetate, butyl acetate, ethyl acetoacetate and 2-ethoxyethyl acetate; diethylene glycol dimethyl ether and propylene glycol monoester. Ethers such as ethyl ether and propylene glycol monoethyl ether acetate;
Aromatic hydrocarbons such as benzene, xylene, toluene, amylbenzene, isopropylbenzene, ethylbenzene, and mesitylene; aliphatic hydrocarbons such as hexane, octane, decane and dodecane; alicyclics such as cyclopentane, cyclohexane and methylcyclohexane Hydrocarbon-based;
N, N-dimethylformamide, N, N-dimethylacetamide, terpenes and the like can be used, and these solvents can be optionally used as a mixed solvent of two or more kinds.

The epoxy resin-based adhesive composition of the present invention may further contain a lubricant, an antistatic agent, a thickener, a thixotropic agent, a dispersant, a flame retardant, a defoaming agent, a reactive or Conventional epoxy resin additives such as non-reactive diluents can also be used.

A preferred composition of the composition of the present invention is a composition containing 5 to 150 parts by weight of the modified amidoamine per 100 parts by weight of the epoxy resin. Further, a more preferable composition of the composition of the present invention is epoxy resin 1
5 to 150 parts by weight of the modified amidoamine
The composition contains parts by weight and 0.01 to 10 parts by weight of a silane coupling agent.

As a method of bonding an adherend (substrate) using the epoxy resin-based adhesive composition of the present invention, for example,
A main component mainly composed of an epoxy resin and a curing agent component mainly composed of the above-mentioned modified amidoamine are kneaded using a kneading machine, and the obtained composition is applied to an adhesive surface to bond an adherend, and if necessary, And drying by heating.

Examples of the kneading machine used here include a change can type mixer, a planetary mixer,
Disper, Henschel mixer, kneader, ink roll, extruder and the like.

The method of applying the composition of the present invention to the adherend is carried out by, for example, a spray, a sealer gun, a brush, a coder or the like.

The epoxy resin adhesive composition of the present invention comprises:
For example, metal, plastic, rubber, glass, wood, paper,
It can be applied to the bonding of substrates such as leather and cloth,
In particular, it can be suitably used when a metal is used as a base material such as metal and metal, metal and plastic, and metal and rubber.

Examples of the metal substrate include aluminum, titanium, stainless steel, mild steel, and plated steel. These are degreased with an organic solvent such as acetone or alcohol, blasted, washed with alkali, and washed with phosphate. processing,
Various surface treatments such as chromate treatment and fluoride salt treatment can also be performed.

As the plastic substrate, for example,
General-purpose resin such as polyethylene, polypropylene, polyvinyl chloride, polyamide, polycarbonate, ABS resin,
Examples include engineering plastics such as FRP resin, and thermosetting resins such as epoxy resin and polyurethane resin.

The rubber substrate includes, for example, natural rubber, isoprene rubber, butadiene rubber, styrene butadiene rubber, acrylonitrile butadiene rubber, acrylic rubber, fluororubber and the like. These may be unvulcanized rubber or vulcanized rubber. Good.

[0041]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto.

Example 1 (Metal-to-Metal Adhesion) A mixture obtained by mixing the following main components and a curing agent component so that the epoxy equivalent / active hydrogen equivalent becomes 1/1 was used as an adhesive. Thickness 1.
0mm steel plate (JIS G-3141 rolled steel plate single side #
280 polished plate) and a steel plate having a thickness of 1.0 mm (the same as above), a test piece of a specified size was prepared, and after deposition, a test piece was prepared at 100 ° C. for 15 minutes.
And then subjected to a tensile shear adhesion strength test (kgf / cm ² ) according to JIS K-6850.
The T-shaped peel strength was measured according to SK-6854 (kgf / 25 mm) (25 ° C.). Further, the test piece after bonding was placed in a thermostatic drier, left at 100 ° C. for 5 hours, and the tensile shear bonding strength and T-peel strength at that temperature were measured. The results are shown in Table 1 below.

[Main agent] wt% EP-4100 (Asahi Denka Kogyo Co., Ltd. bisphenol A type epoxy resin 70, epoxy equivalent 190) Hiker CTBN 1300X8 (Ube Industries, Ltd. carboxy-modified nitrile rubber) 29 γ-aminopropyl Triethoxysilane 1

[Curing Agent]% by weight Amine compound (see Table 1 below) 100

[0045]

[Table 1]

The details of the amine compounds in the above [Table 1] are as follows.
It is as shown below. * 1: A-NH-CO-CH (R) CH ₂ -NH-B
[The above general formula (I)] PA-1 R = -HA, B = residue of diethylenetriamine PA-2 R = -HA, B = residue of tetraethylenepentamine PA-3 R = -HA, B = residue of isophoronediamine PA-4 R = —CH ₃ A, B = residue of tetraethylenepentamine

* 2 PA-5 Triethylenetetramine PA-6 Isophoronediamine PA-7 Versamide 140 (polyamide amine manufactured by Fuji Kasei Co., Ltd.)

* 3 PA-1 / PA-5 = 4/1 PA-1 / PA-6 = 4/1

Example 2 (Adhesion of Metal-Rubber) As an adhesive, a mixture obtained by mixing the following main component and curing agent so that the epoxy equivalent / active hydrogen equivalent was 1/1 was used. Thickness 1.
A test piece of a specified size was prepared from a 0 mm steel plate (same as that used in Example 1) and a 0.5 mm thick sulfur-vulcanized nitrile rubber film, and heated at 100 ° C. for 15 minutes after the application. Then, the tensile shear adhesive strength (kgf / cm ² ) was measured according to JIS K-6850 (25 ° C.).
Further, the test piece after bonding was placed in a thermostatic dryer, left at 100 ° C. for 5 hours, and the tensile shear bonding strength at that temperature was measured. The results are shown in Table 2 below.

[Main agent] wt% EP-4100 (bisphenol A type epoxy resin manufactured by Asahi Denka Kogyo KK) 40 talc 59 γ-aminopropyltriethoxysilane 1

[Curing Agent] Weight% Amine compound (see [Table 2] below) 50 Talc 30 Calcium carbonate 15 Carbon black 5

[0052]

[Table 2]

* 4 and * 5 in the above [Table 2] mean the following. * 4: PA-1 / PA-5 = 4/1 PA-1 / PA-6 = 4/1 * 5: The material was broken at the rubber part.

Example 3 (Metal-Plastic Bonding) The following main component and curing agent component were used as an adhesive with an epoxy equivalent / active hydrogen equivalent of 1
/ 1.0 mm steel plate as the adherend (same as that used in Example 1)
And a 1.0 mm thick polyester glass (Musashino Kasei product of Japan Test Panel Co., Ltd .: glass fiber reinforced unsaturated polyester resin) to prepare a test piece of specified size, and after heating, heat at 100 ° C. for 15 minutes. JIS K-6
Tensile shear bond strength according to 850 (kgf / cm ² )
Was measured (25 ° C.). Further, the test piece after bonding was placed in a thermostatic dryer, left at 100 ° C. for 5 hours, and the tensile shear bonding strength at that temperature was measured. The results are shown in Table 3 below.

[Main Agent] Weight% EP-4100 (Bisphenol A epoxy resin manufactured by Asahi Denka Kogyo Co., Ltd.) 40 Talc 59 γ-aminopropyltriethoxysilane 1

[Curing Agent] Weight% Amine compound (see [Table 3] below) 60 Talc 40

[0057]

[Table 3]

Note that * 6 and * 7 in the above [Table 3] mean the following. * 6 PA-1 / PA-5 = 4/1 PA-1 / PA-6 = 4/1 * 7 Material rupture: Measurement was impossible because the polyester glass portion was broken.

As is clear from the above Examples and Comparative Examples, an epoxy resin-based adhesive composition obtained by combining an epoxy resin with a general polyamine compound such as triethylenetetramine or isophoronediamine was used (Comparative Example 1). -1,1-2,2-1,2-2,3-1,3-
2) Adhesion when metal is used as a base material such as metal-to-metal, metal-to-rubber or metal-to-plastic, is insufficient, and furthermore, its performance is deteriorated at high temperatures.
When a known polyamidoamine compound is combined as a curing agent for an epoxy resin (Comparative Examples 1-3, 2-3, and 3
In the case of -3), the adhesion at room temperature is improved, but the performance is significantly reduced at high temperature.

On the other hand, by using the modified amidoamine represented by the general formula (I) according to the present invention as a curing agent, the adhesion at room temperature is excellent, and the performance is almost deteriorated even at high temperature. (Examples 1-1 to 1-6, 2-1 to 2-6, and 3-1)
３−3-6).

[0061]

The epoxy resin-based adhesive composition of the present invention has excellent heat-resistant adhesiveness and can be effectively used as a structural adhesive.

Claims (5)

[Claims] 1. An epoxy resin adhesive composition comprising an epoxy resin and a modified amidoamine represented by the following general formula (I). Embedded image 2. The epoxy resin-based adhesive composition according to claim 1, wherein the polyamine compound constituting the residues represented by A and B in the general formula (I) is an aliphatic polyamine. 3. The epoxy resin adhesive composition according to claim 1, further comprising 0.01 to 10 parts by weight of at least one silane coupling agent based on 100 parts by weight of the epoxy resin. Stuff. 4. The epoxy resin according to claim 1, wherein the epoxy resin is an epoxy resin represented by the following general formula (II).
The epoxy resin-based adhesive composition according to any one of the above. Embedded image 5. The epoxy resin-based adhesive composition according to claim 1, wherein the epoxy resin-based adhesive composition is used for an application using a metal as a substrate.